Can Asparagus Be Grown in Containers?

Asparagus is ready for harvest during an 8 to 12 week period during the spring, and again in fall.

Asparagus (Asparagus officinalis) is a perennial vegetable that thrives in U.S. Department of Agriculture plant hardiness zones 4 through 8. Grown for its tender edible shoots, asparagus requires two years of growth before the spears are ready for harvest. A well-cared-for asparagus plant produces a fresh crop of shoots each season for 8 to 10 years, although some plants remain productive up to 20 years. Due to its size asparagus is not typically meant for container-growing; however this can be achieved with a very large planter, although this shortens the life-span of the plant.

Adequate Space

Because asparagus is a perennial vegetable that requires two years to become established and reach maturity, it needs a permanent space in the garden landscape. It also needs adequate growing space, as the fern-like foliage reaches heights between 1 and 3 feet, with a width between 3 and 6 feet. For this reason, asparagus is not typically recommended for container planting. Most containers are not large enough to accommodate asparagus. If you have the room in your garden asparagus thrives when planted directly in the ground or in a large raised bed with ample space. It is important to carefully consider your planting space, due to asparagus’ longevity once it becomes established.

Container-Growing Limitations

While asparagus is not generally recommended for container-growing, it is not impossible to achieve an asparagus crop from a planter. However, there are some limitations. First, it is important to find a container that is large enough and wide enough to house the plant. It should be about 16 gallons. Secondly, container-grown asparagus does not live as long as crowns planted in the ground or a raised bed. Following the two-year establishment period, container-grown asparagus only produces a crop for three to four years under ideal conditions. Considering the work and waiting time needed to grow an asparagus crop, this may or may not be worth it to you, especially since plants grown outside a container last and produce crops for many more seasons.

Tips for Containers

Asparagus is best planted during the months of October through March. When planting from seed, start your asparagus indoors in flats that are 1 1/2 inches deep. Crowns require 1 year before they are ready for transplant. When transplanting into a container, plant one crown per container.Choose a large container, approximately 7 to 8 inches deep and at least 3 to 6 feet wide to accommodate the size of the plant at maturity. If you have limited outdoor space, container-growing asparagus can thrive indoors in a window that receives full sun. Asparagus is able to develop spears at room temperature. However, it is important to note that your plant does require cooler temperatures for dormancy during the winter months; therefore it is important to find a space and move your containers outdoors during this time.

Other Growing Requirements

Asparagus is a full-sun plant that requires temperatures between 65 and 85 degrees to thrive. Soil temperatures below 50 degrees inhibit spear production, while temperatures above 85 degrees damage the quality and flavor of the vegetable. Plant asparagus in a sunny area that is also protected from heavy winds. Loose, fertile, well-draining soil with a pH of 6.5 to 7.5 is needed for healthy plants. Soils that are higher in acidity decrease crop yields, while heavy clay soils cause problems with drainage. You may notice asparagus spear developing within a few weeks to a few months after planting your crowns; however, do not harvest spears until the plant has reached its two-year establishment. Otherwise, you run the risk of damaging the crop or weakening the plant.